add cli option to download all manifests

- Add `all-manifests` option to both `ctr content fetch` and `ctr
  images pull`. By default it is false.
- This option ties to `AppendDistributionSourceLabel` in client.

Signed-off-by: Yu Yi <yiyu@google.com>

pull.go

@@ -140,9 +140,14 @@ func (c *Client) fetch(ctx context.Context, rCtx *RemoteContext, ref string, lim
 		childrenHandler := images.ChildrenHandler(store)
 		// Set any children labels for that content
 		childrenHandler = images.SetChildrenLabels(store, childrenHandler)
-		// Filter manifests by platforms but allow to handle manifest
-		// and configuration for not-target platforms
-		childrenHandler = remotes.FilterManifestByPlatformHandler(childrenHandler, rCtx.PlatformMatcher)
+		if rCtx.AppendDistributionSourceLabel {
+			// Filter manifests by platforms but allow to handle manifest
+			// and configuration for not-target platforms
+			childrenHandler = remotes.FilterManifestByPlatformHandler(childrenHandler, rCtx.PlatformMatcher)
+		} else {
+			// Filter children by platforms if specified.
+			childrenHandler = images.FilterPlatforms(childrenHandler, rCtx.PlatformMatcher)
+		}
 		// Sort and limit manifests if a finite number is needed
 		if limit > 0 {
 			childrenHandler = images.LimitManifests(childrenHandler, rCtx.PlatformMatcher, limit)